#include "Snake.h"
//设置光标的坐标
void SetPos(short x, short y)
{
	COORD pos = { x, y };
	HANDLE hOutput = NULL;
	//获取标准输出的句柄(⽤来标识不同设备的数值)
	hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
	//设置标准输出上光标的位置为pos
	SetConsoleCursorPosition(hOutput, pos);
}
void WelcomeToGame()
{
	SetPos(40, 15);
	printf("欢迎来到贪吃蛇⼩游戏");
	SetPos(40, 25);//让按任意键继续的出现的位置好看点
	system("pause");
	system("cls");
	SetPos(25, 12);
	printf("⽤ ↑ . ↓ . ← . → 分别控制蛇的移动， F3为加速，F4为减速\n");
	SetPos(25, 13);
	printf("加速将能得到更⾼的分数。\n");
	SetPos(40, 25);//让按任意键继续的出现的位置好看点
	system("pause");
	system("cls");
}
void CreateMap()
{
	int i = 0;
	//上(0,0)-(56, 0)
	SetPos(0, 0);
	for (i = 0; i < 58; i += 2)
	{
		wprintf(L"%c", WALL);
	}
	//下(0,26)-(56, 26)
	SetPos(0, 26);
	for (i = 0; i < 58; i += 2)
	{
		wprintf(L"%c", WALL);
	}
	//左
	//x是0，y从1开始增⻓
	for (i = 1; i < 26; i++)
	{
		SetPos(0, i);
		wprintf(L"%c", WALL);
	}
	//x是56，y从1开始增⻓
	for (i = 1; i < 26; i++)
	{
		SetPos(56, i);
		wprintf(L"%c", WALL);
	}
}
void InitSnake(pSnake ps)
{
	pSnakeNode cur = NULL;
	int i = 0;
	//创建蛇⾝节点，并初始化坐标
	//头插法
	for (i = 0; i < 5; i++)
	{
		//创建蛇⾝的节点
		cur = (pSnakeNode)malloc(sizeof(SnakeNode));
		if (cur == NULL)
		{
			perror("InitSnake()::malloc()");
			return;
		}
		//设置坐标
		cur->next = NULL;
		cur->x = POS_X + i * 2;
		cur->y = POS_Y;
		//头插法
		if (ps->_pSnake == NULL)
		{
			ps->_pSnake = cur;
		}
		else
		{
			cur->next = ps->_pSnake;
			ps->_pSnake = cur;
		}
	}
	//打印蛇的⾝体
	cur = ps->_pSnake;
	while (cur)
	{
		SetPos(cur->x, cur->y);
		wprintf(L"%c", BODY);
		cur = cur->next;
	}
	//初始化贪吃蛇数据
	ps->_SleepTime = 200;
	ps->_Socre = 0;
	ps->_Status = OK;
	ps->_Dir = RIGHT;
	ps->_foodWeight = 10;
}
void CreateFood(pSnake ps)
{
	int x = 0;
	int y = 0;
again:
	//产⽣的x坐标应该是2的倍数，这样才可能和蛇头坐标对⻬。
	do
	{
		x = rand() % 53 + 2;
		y = rand() % 25 + 1;
	} while (x % 2 != 0);
	pSnakeNode cur = ps->_pSnake;//获取指向蛇头的指针
	//⻝物不能和蛇⾝冲突
	while (cur)
	{
		if (cur->x == x && cur->y == y)
		{
			goto again;
		}
		cur = cur->next;
	}
	pSnakeNode pFood = (pSnakeNode)malloc(sizeof(SnakeNode)); //创建⻝物
	if (pFood == NULL)
	{
		perror("CreateFood::malloc()");
		return;
	}
	else
	{
		pFood->x = x;
		pFood->y = y;
		SetPos(pFood->x, pFood->y);
		wprintf(L"%c", FOOD);
		ps->_pFood = pFood;
	}
}
void PrintHelpInfo()
{
	//打印提⽰信息
	SetPos(64, 15);
	printf("不能穿墙，不能咬到⾃⼰\n");
	SetPos(64, 16);
	printf("⽤↑.↓.←.→分别控制蛇的移动.");
	SetPos(64, 17);
	printf("F3 为加速，F4 为减速\n");
	SetPos(64, 18);
	printf("ESC ：退出游戏.space：暂停游戏.");
	SetPos(64, 20);
	printf("⽐特就业课@版权");
}
void pause()//暂停
{
	while (1)
	{
		Sleep(300);
		if (KEY_PRESS(VK_SPACE))
		{
			break;
		}
	}
}
//pSnakeNode psn 是下⼀个节点的地址
//pSnake ps 维护蛇的指针
int NextIsFood(pSnakeNode psn, pSnake ps)
{
	return (psn->x == ps->_pFood->x) && (psn->y == ps->_pFood->y);
}
//pSnakeNode psn 是下⼀个节点的地址
//pSnake ps 维护蛇的指针
void EatFood(pSnakeNode psn, pSnake ps)
{
	//头插法
	psn->next = ps->_pSnake;
	ps->_pSnake = psn;
	pSnakeNode cur = ps->_pSnake;
	//打印蛇
	while (cur)
	{
		SetPos(cur->x, cur->y);
		wprintf(L"%c", BODY);
		cur = cur->next;
	}
	ps->_Socre += ps->_foodWeight;
	free(ps->_pFood);
	CreateFood(ps);
}
//pSnakeNode psn 是下⼀个节点的地址
//pSnake ps 维护蛇的指针
void NoFood(pSnakeNode psn, pSnake ps)
{
	//头插法
	psn->next = ps->_pSnake;
	ps->_pSnake = psn;
	pSnakeNode cur = ps->_pSnake;
	//打印蛇
	while (cur->next->next)
	{
		SetPos(cur->x, cur->y);
		wprintf(L"%c", BODY);
		cur = cur->next;
	}
	//最后⼀个位置打印空格，然后释放节点
	SetPos(cur->next->x, cur->next->y);
	printf(" ");
	free(cur->next);
	cur->next = NULL;
}
//pSnake ps 维护蛇的指针
int KillByWall(pSnake ps)
{
	if ((ps->_pSnake->x == 0)
		|| (ps->_pSnake->x == 56)
		|| (ps->_pSnake->y == 0)
		|| (ps->_pSnake->y == 26))
	{
		ps->_Status = KILL_BY_WALL;
		return 1;
	}
	return 0;
}
//pSnake ps 维护蛇的指针
int KillBySelf(pSnake ps)
{
	pSnakeNode cur = ps->_pSnake->next;
	while (cur)
	{
		if ((ps->_pSnake->x == cur->x)
			&& (ps->_pSnake->y == cur->y))
		{
			ps->_Status = KILL_BY_SELF;
			return 1;
		}
		cur = cur->next;
	}
	return 0;
}
void SnakeMove(pSnake ps)
{
	//创建下⼀个节点
	pSnakeNode pNextNode = (pSnakeNode)malloc(sizeof(SnakeNode));
	if (pNextNode == NULL)
	{
		perror("SnakeMove()::malloc()");
		return;
	}
	//确定下⼀个节点的坐标，下⼀个节点的坐标根据，蛇头的坐标和⽅向确定
	switch (ps->_Dir)
	{
	case UP:
	{
		pNextNode->x = ps->_pSnake->x;
		pNextNode->y = ps->_pSnake->y - 1;
	}
	break;
	case DOWN:
	{
		pNextNode->x = ps->_pSnake->x;
		pNextNode->y = ps->_pSnake->y + 1;
	}
	break;
	case LEFT:
	{
		pNextNode->x = ps->_pSnake->x - 2;
		pNextNode->y = ps->_pSnake->y;
	}
	break;
	case RIGHT:
	{
		pNextNode->x = ps->_pSnake->x + 2;
		pNextNode->y = ps->_pSnake->y;
	}
	break;
	}
	//如果下⼀个位置就是⻝物
	if (NextIsFood(pNextNode, ps))
	{
		EatFood(pNextNode, ps);
	}
	else//如果没有⻝物
	{
		NoFood(pNextNode, ps);
	}
	KillByWall(ps);
	KillBySelf(ps);
}
void GameStart(pSnake ps)
{
	//设置控制台窗⼝的⼤⼩，30⾏，100列
	//mode 为DOS命令
	system("mode con cols=100 lines=30");
	//设置cmd窗⼝名称
	system("title 贪吃蛇");
	//获取标准输出的句柄(⽤来标识不同设备的数值)
	HANDLE hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
	//影藏光标操作
	CONSOLE_CURSOR_INFO CursorInfo;
	GetConsoleCursorInfo(hOutput, &CursorInfo);//获取控制台光标信息
	CursorInfo.bVisible = false; //隐藏控制台光标
	SetConsoleCursorInfo(hOutput, &CursorInfo);//设置控制台光标状态
	//打印欢迎界⾯
	WelcomeToGame();
	//打印地图
	CreateMap();
	//初始化蛇
	InitSnake(ps);
	//创造第⼀个⻝物
	CreateFood(ps);
}
void GameRun(pSnake ps)
{
	//打印右侧帮助信息
	PrintHelpInfo();
	do
	{
		SetPos(64, 10);
		printf("得分：%d ", ps->_Socre);
		printf("每个⻝物得分：%d分", ps->_foodWeight);
		if (KEY_PRESS(VK_UP) && ps->_Dir != DOWN)
		{
			ps->_Dir = UP;
		}
		else if (KEY_PRESS(VK_DOWN) && ps->_Dir != UP)
		{
			ps->_Dir = DOWN;
		}
		else if (KEY_PRESS(VK_LEFT) && ps->_Dir != RIGHT)
		{
			ps->_Dir = LEFT;
		}
		else if (KEY_PRESS(VK_RIGHT) && ps->_Dir != LEFT)
		{
			ps->_Dir = RIGHT;
		}
		else if (KEY_PRESS(VK_SPACE))
		{
			pause();
		}
		else if (KEY_PRESS(VK_ESCAPE))
		{
			ps->_Status = END_NOMAL;
			break;
		}
		else if (KEY_PRESS(VK_F3))
		{
			if (ps->_SleepTime >= 50)
			{
				ps->_SleepTime -= 30;
				ps->_foodWeight += 2;
			}
		}
		else if (KEY_PRESS(VK_F4))
		{
			if (ps->_SleepTime < 350)
			{
				ps->_SleepTime += 30;
				ps->_foodWeight -= 2;
				if (ps->_SleepTime == 350)
				{
					ps->_foodWeight = 1;
				}
			}
		}
		//蛇每次⼀定之间要休眠的时间，时间短，蛇移动速度就快
		Sleep(ps->_SleepTime);
		SnakeMove(ps);
	} while (ps->_Status == OK);
}
void GameEnd(pSnake ps)
{
	pSnakeNode cur = ps->_pSnake;
	SetPos(24, 12);
	switch (ps->_Status)
	{
	case END_NOMAL:
		printf("您主动退出游戏\n");
		break;
	case KILL_BY_SELF:
		printf("您撞上⾃⼰了 ,游戏结束!\n");
		break;
	case KILL_BY_WALL:
		printf("您撞墙了,游戏结束!\n");
		break;
	}
	//释放蛇⾝的节点
	while (cur)
	{
		pSnakeNode del = cur;
		cur = cur->next;
		free(del);
	}
}